Feature

Bees in crisis

The humble bee is one of the most important insects on Earth. Around the world, these tiny, tireless workers are under siege and disappearing fast, with a sting in the tail for all of us.

Australia’s main honey bee species, the European honey bee (Apis mellifera), was introduced in the 1820s.

Credit: iStockphoto

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There’s good reason for the old cliché of the ‘busy bee’. The short lives of some of nature’s hardest workers are spent on long trips to gather honey-making nectar as far as 10 km from the hive. As they fly from plant to plant, bees pollinate many of our plants and agricultural crops.

Their toil not only results in the honey you see on the supermarket shelf or your local farmers’ market, but also plays a hand in a huge percentage of the food on our plates. One of every three mouthfuls of food we eat is the result of insect pollination, while honey bees also pollinate food for native animals and play a big role in maintaining biodiversity.

Australia’s main honey bee species, the European honey bee (Apis mellifera), was introduced in the 1820s. It is an industrious pollinator in managed hives and in the wild. But in recent years, our worker bees have been abruptly disappearing from their hives – part of a worldwide phenomenon that has been given the name colony collapse disorder (CCD).

According to a 2010 United Nations Environment Programme report on CCD, Europe is experiencing “unusual weakening and mortality in colonies” while the US battles “drastic losses”. So far Australia has dodged the worst of what’s happening overseas, but we now face most of the same threats.

“My family have been bee-keepers for four generations,” says Jodie Goldsworthy of Beechworth Honey, based in Corowa, NSW. “The past five years of bee-keeping have been the hardest ever... and the most frustrating.”

So what’s causing these hard-working honey hoarders to suddenly drop like flies? Habitat loss, diseases, invasive species and agricultural insecticides are thought to be among the barrage of contributing factors.

One of the invasive species causing havoc is the small hive beetle, a pest introduced by means unknown and first identified in Australia in 2002. “Basically it’s an opportunistic scavenger,” says Des Cannon from the Rural Industries Research and Development Corporation Honeybee Advisory Committee. “It finds a weak hive and moves in.” Once ensconced in its new home, the adult beetle lays larvae-bearing eggs that infest and destroy the hive.

Still reeling from the invasion of small hive beetles, Australian bee-keepers were more recently stung by news that the Asian bee (Apis cerana) had become our latest unwanted guest. A close cousin of the European honey bee, it was discovered in Cairns in May 2007. Since then, more than 300 swarms of the pest have been destroyed.

Asian bees compete with European bees for nectar and steal honey from managed hives, which can lead to the starvation of those colonies. They’re also the natural host of varroa (Varroa destructor), a bee mite that has wiped out commercial and feral hives around the world. Australia is the only major bee-keeping country not yet hit by this hitchhiking parasite.

Vampires the size of a pinhead, varroa suck the blood of bees. If left untreated, an infested colony will eventually die. “It’s the major pest of bee populations worldwide,” says CSIRO research scientist Denis Anderson, who named the species. “There’s a high chance of it coming to Australia,” he adds.

“The Asian bee had a severe impact when it was introduced to the Solomon Islands in 2003, reducing to just five the number of managed hives by the year 2008 – from a starting point of 2,000 hives,” says
Beechworth Honey’s Goldsworthy.

It’s not just Australia’s honey industry at stake. In competing with possums, nectar-eating birds and native bees for food and shelter, the new Asian bee species could have serious repercussions for biodiversity. As Anderson explains: “It is smaller and can use smaller cavities [for nesting] meaning the density will be higher in the bush. Most possum and bird cavities are quite small... we’ve already found a swarm that killed the birds in the cavity where they were nesting.”

“This is not something that can be managed, it must be eradicated and destroyed or we live with it forever,” says Goldsworthy. She is one of many bee-keepers, farmers and green groups lobbying the Australian Government to increase and maintain Asian bee eradication efforts following a decision to cut funding earlier this year.

If, or more likely when, varroa does arrive, bee-keepers could protect their hives with miticides – which are strong pesticides.

“There’s an insidious impact. We have a lot of feral [European] bees in the bush and these do most of the pollination of native plants,” says Anderson. “This free pollination would dry up.”

“We could certainly live without honey, the problem is if we don’t have the bees, we don’t have pollination,” says Goldsworthy. And without pollination, there’s no food security.

And humans aren’t the only ones who could be left hungry. “For our particular repertoire of native plants, the 1,500 species of native bee have evolved with them,” says Anne Dollin from the Australian Native Bee Research Centre. “If we lose them, we lose the pollinators for our native trees.” As those plants provide food for native animals, the impact spreads through the ecosystem.

“There are complex, cumulative and interrelated threats faced by honey bees,” says Goldsworthy. One that has been linked to CCD is exposure to pesticides. Of particular concern is a class of insecticides known as neonicatinoids – the most widely used worldwide – which act on the central nervous system of insects. Unlike other pesticides that are sprayed onto crops, neonicatinoids are applied as a seed coating so the chemical concoction is taken up through the plant into the pollen where it’s available to bees.

“We acknowledge there is significant concern around the world about neonicotinoids related to CCD,” says Felicity McDonald from the Australian Pesticides and Veterinary Medicines Authority, “but we have not experienced the same effects of CCD as overseas, despite neonicotinoids being available in Australia for several years.”

Habitat destruction also takes its toll. “When large areas of bush are cleared for residential areas, the population is destroyed,” says Dollin. Remaining green areas such as ovals are typically absent of nectar or nesting places. Add climate change and air pollution to the long list of threats facing bees, and their future looks grim.

Though Australia has so far avoided the large declines happening in Europe and the USA, we need to prepare for the coming storm.

---------------------------------Want to know what you can do to help? Keep an eye out in next week’s e-Newsletter to learn more about backyard bee-keeping and creating a bee-friendly garden. There's a sign-up to subscribe to the eNewsletter on the right of every page of the G website.